The present invention relates to a light emitting diode (LED) device used in electronic devices such as a portable telephone.
FIG. 4 is a sectional view of a conventional LED device. The LED device 15 comprises a substrate 25, a frame 18 made of resin and having a semispherical recess 19, electrodes 17a and 17b embedded in the substrate 18, and an LED 16 secured to the electrode 17a. The LED 16 is connected to the electrodes 17a and 17b by lead wires 20. The inside wall 22 of the recess 19 is processed into a light reflection surface 22. The recess 19 is charged with a transparent resin 21 to seal the LED.
In the LED device 15, if moisture remains in the transparent resin 21, the frame 18 is cracked by expansion of the moisture caused by the heat of the reflow soldering. Furthermore, the transparent resin 21 contracts in dependency on the change of the atmospheric temperature. If the change repeats, lead wires 20 may be cut, which results in unreliableness of the device.